Level 2

Where is online tax calculator for self-employed person?

Which online tax calculator I can use to approximately calculate ALL taxes (both feral and local state tax) I owed in 2018? I have been selling on eBay since last year and never filed any tax yet in U.S. I’ve already worked out schedule C (Profit or Loss From Business) to get my net profit in 2017. I found many web sites that help compute tax but unfortunately they are almost all for employee, not self-employed person. 

I appreciate if someone can give a link for the web page.